Ancient Romanian Ice Cave Bacterium Carries 100+ Resistance Genes, Defies 10 Antibiotics

A Frontiers in Microbiology study details Psychrobacter SC65A.3 isolated from a 5,000-year-old ice core in Romania’s Scărișoara Ice Cave. Genomic analysis reveals over 100 antibiotic-resistance genes (and ~600 genes of unknown function) and resistance to ten modern antibiotics, including ciprofloxacin. While thawing ice due to climate change could release resistance genes into contemporary bacteria, the enzymes and compounds from this ancient microbe also offer potential biotechnological applications; the finding underscores the need for monitoring ancient genomes as glaciers and caves thaw and consider implications for antimicrobial resistance.